These routines are used to initiate TLS processing on an LDAP session.
ldap_start_tls_s() sends a StartTLS request to a server, waits for the reply, and then installs
TLS handlers on the session if the request succeeded. The routine returns
LDAP_SUCCESS if everything succeeded, otherwise it returns an LDAP error code.
ldap_start_tls() sends a StartTLS request to a server and does nothing else. It returns
LDAP_SUCCESS if the request was sent successfully.
ldap_tls_inplace() returns 1 if TLS handlers have been installed on the specified session, 0
otherwise.
ldap_install_tls() installs the TLS handlers on the given session. It returns
LDAP_LOCAL_ERROR if TLS is already installed.